Naslov
Populacije oligoheta u biocenozama rijeke Save (598-751, 2 km)
(THE POPULATIONS OF OLIGOCHAETA IN THE BIOCOENOSES OF THE RIVER SAVA (598-751, 2 km))

Autori
Kerovec, Mladen ; Meštrov, Milan

Vrsta, podvrsta i kategorija rada
Radovi u zbornicima skupova, cjeloviti rad (in extenso), znanstveni

Izvornik
Zbornik radova II. kongresa ekologa Jugoslavije. Knjiga II / Rauš, Đuro - Zagreb : Savez društava ekologa Jugoslavije, 1979, 1789-1802

Skup
II. kongresa ekologa Jugoslavije

Mjesto i datum
Zadar, Hrvatska; NP Plitvička jezera, Hrvatska, 01.10.1979. - 07.10.1979

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Domaća recenzija

Ključne riječi
Oligochaeta; rijeka Sava
(Oligochaeta; river Sava)

Sažetak
In the section of the river Sava from Krško (751.2 km) to Sisak (598 km), we may separate two parts which are considerably different in ecological features, which is also clearly reflected in the biocenological aspect. The watercourse of the first part, which includes the section of the river from Krško to Podsused is faster, with a gravel bed and with more than 50% specimens of Oligochaeta species in the biocoenoses of the river bed. Only at Krško1 station, Oligochaeta occur in 16.9% in the macrozoobenthos. In this part of the river, the share of the groups of indicators in Oligochaeta populations consisted of species Tubifex tubifex, Limnodrilus hoffmeisteri, L. udecemianus, in less than 50% and at Krško1 station it hardly surpasses 10%. Among the macroscopical animals in the periphyton Oligochaeta are predominant (66.4%), and the family Naididae represents the largest part of the Oligochaeta, population (66.8%). In the seston we can only find animals which have been drifted off from the biocoenoses of the benthos or the periphyton from the upstream parts. The second part includes the section of the river from Oborovo to Sisak with a sandy-silty bed. The main characteristic of this part is a small variety of species in the biocoenoses of the benthos. The density of the Oligochaeta population, which represents 91.9% in the macrozoobenthos, is quite high, and the highest values were noted in the spring of 1976 with the average number of specimens amounting to 21, 656 in 0.5 L of the sediment. Species indicators of polysaprobic degree of pollution, T. tubifex, L. hofmeisteri and L. udekemianus, represent the main part of the population of all Oligochaeta in the biocoenoses of the benthos (95.3%). Only at Sisak power station, the group of indicators represents a considerably smaller portion in the Oligochaeta population (61.3%). In the periphyton communities, which are here developed exclusively on ferry-beats and other floating craft, Oligochaeta (79.6°/o) and larvae of Chiro-nomidae (18.4*Voi) are predominant among other macroscopical animals. The family Naididae is the most numerous in species (9) and it represents over 95°/o of the population of all Oligochaeta in the periphytin. If we take into account all varieties of communities which live on the benthos, then the portion of Oligochaeta in the macrozoobenthos and the portion of the group of indicators consisting of the species T. tubifex, L. hoffmeisteri and L. udekemianus, which is directly connected with the intensity of pollution, we may roughly classify the examined section of the river Sava according to intensity of pollution as presented in Tab. 2. The Sava upstream from Krško (station K1) is less polluted, while the part of the river downstream from Krško is moderately polluted (stations K2 B, J, Po.). The part of the river from Ivanja Rijeka, from the point where the main collector of Zagreb empties into the river, to Galdovo (stations O, P1, P2, D, T, G) is heavily and almost steadily polluted. In Sisak, downstream from the mouth of the river Kupa into the Sava (power station Sisak), the degree of pollution is considerably lower than at upstream stations, mainly due to the influence of less leaded water of the Kupa and the processes of self-purification. These investigations indicate that it is possible to use Gross's approach (1976) effectively in our regions too.

Izvorni jezik
Hrvatski

Znanstvena područja
Biologija

POVEZANOST RADA